This example creates and updates a standard Battery Level service containing a single GATT characteristic. The battery service transmits a device's battery level in percentage, with 100% being a fully charged battery and 0% being a fully drained battery. The canonical source for this example lives at https://github.com/ARMmbed/mbed-os-example-ble/tree/master/BLE_BatteryLevel

This example creates and updates a standard Battery Level service containing a single GATT characteristic.

The battery service transmits a device's battery level in percentage, with 100% being a fully charged battery and 0% being a fully drained battery.

Although the sample application runs on a BLE device, it doesn't show the device's real battery level (because that changes very slowly and will make for a dull example). Instead, it transmits a fake battery level that starts at 50% (half charged). Every half second, it increments the battery level, going in single increments until reaching 100% (as if the battery is charging). It then drops down to 20% to start incrementing again.

Running the application

Requirements

The sample application can be seen on any BLE scanner on a smartphone. If you don't have a scanner on your phone, please install :

- nRF Master Control Panel for Android.

- LightBlue for iPhone.

Hardware requirements are in the main readme.

Building instructions

Building with mbed CLI

If you'd like to use mbed CLI to build this, then you should refer to the main readme. The instructions here relate to using the developer.mbed.org Online Compiler

In order to build this example in the mbed Online Compiler, first import the example using the ‘Import’ button on the right hand side.

Next, select a platform to build for. This must either be a platform that supports BLE, for example the NRF51-DK, or one of the following:

List of platforms supporting Bluetooth Low Energy

Or you must also add a piece of hardware and the supporting library that includes a Bluetooth Low Energy driver for that hardware, for example the K64F or NUCLEO_F401RE with the X-NUCLEO-IDB05A1

List of components supporting Bluetooth Low Energy.

Once you have selected your platform, compile the example and drag and drop the resulting binary onto your board.

For general instructions on using the mbed Online Compiler, please see the mbed Handbook

Checking for success

Note: Screens captures depicted below show what is expected from this example if the scanner used is nRF Master Control Panel version 4.0.5. If you encounter any difficulties consider trying another scanner or another version of nRF Master Control Panel. Alternative scanners may require reference to their manuals.

  • Build the application and install it on your board as explained in the building instructions.
  • Open the BLE scanner on your phone.
  • Start a scan.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/start_scan.png

figure 1 How to start scan using nRF Master Control Panel 4.0.5

  • Find your device; it should be named `BATTERY`.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/scan_result.png

figure 2 Scan results using nRF Master Control Panel 4.0.5

  • Establish a connection with your device.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/connection.png

figure 3 How to establish a connection using Master Control Panel 4.0.5

  • Discover the services and the characteristics on the device. The *Battery service* has the UUID 0x180F and includes the *Battery level* characteristic which has the UUID 0x2A19.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/discovery.png

figure 4 Representation of the Battery service using Master Control Panel 4.0.5

  • Register for the notifications sent by the *Battery level* characteristic.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/register_to_notifications.png

figure 5 How to register to notifications using Master Control Panel 4.0.5

  • You should see the battery level value change every half second. It begins at 50, goes up to 100 (in steps of 1), resets to 20 and so on.

https://developer.mbed.org/teams/mbed-os-examples/code/mbed-os-example-ble-BatteryLevel/raw-file/a5ac4bf2e468/img/notifications.png

figure 6 Notifications view using Master Control Panel 4.0.5

If you can see the characteristic, and if its value is incrementing correctly, the application is working properly.

Changes

RevisionDateWhoCommit message
81:99e70947653f 2019-08-15 mbed_official Merge pull request #252 from donatieng/mbed_os_update default tip
80:1170721a1db6 2019-02-27 mbed_official Updating mbed-os to mbed-os-5.11.5
79:816f08ee21bd 2019-02-25 mbed_official Merge pull request #217 from adbridge/master
78:b300982f35aa 2019-02-13 mbed_official Updating mbed-os to mbed-os-5.11.2
77:634599d24f93 2019-01-14 mbed_official Merge pull request #207 from adbridge/master
76:e489712bcbcf 2019-01-14 mbed_official Merge pull request #208 from ARMmbed/mbed-os-5.11.0-oob
75:a91805e80107 2018-12-14 mbed_official Updating mbed-os to mbed-os-5.10.4
74:eee554d9917b 2018-11-16 mbed_official Merge pull request #192 from paul-szczepanek-arm/update-libs
73:e76cb6fa4310 2018-11-07 mbed_official Merge pull request #189 from ARMmbed/donatieng-patch-1
72:15a6111a679e 2018-10-22 mbed_official Merge pull request #187 from cmonr/master
71:d083bf017556 2018-09-26 mbed_official Merge pull request #183 from ARMmbed/mbed-os-5.10.0-oob
70:5cf292205001 2018-09-04 mbed_official Merge pull request #173 from pan-/use-cordio
69:3505c21fe0fc 2018-08-29 mbed_official Merge pull request #172 from 0xc0170/master
68:6b40c380545f 2018-08-23 mbed_official Updating mbed-os to mbed-os-5.9.5
67:2a65e8c6ab62 2018-08-08 mbed_official Merge pull request #168 from cmonr/master
66:0a5868d3e297 2018-07-18 mbed_official Merge pull request #166 from cmonr/master
65:a7d40a1e5bb3 2018-07-06 mbed_official Merge pull request #163 from adbridge/master
64:31a307a8a873 2018-06-22 mbed_official Merge pull request #160 from adbridge/master
63:4a5567d7354e 2018-06-20 mbed_official Merge pull request #159 from ARMmbed/mbed-os-5.9.0-oob
62:42a62fe25296 2018-06-11 mbed_official Merge pull request #158 from adbridge/master
61:2430255789dc 2018-06-05 mbed_official Initial commit.
60:b3931d7acd8d 2018-04-04 mbed_official Merge pull request #141 from adbridge/master
59:7288d623447c 2018-04-04 mbed_official Merge pull request #142 from ARMmbed/mbed-os-5.8.0-oob
58:0e470fa26478 2018-03-23 mbed_official Merge pull request #139 from cmonr/master
57:b5b1c99d74c7 2018-03-23 mbed_official Merge pull request #137 from adbridge/master
56:06f9f9fe6687 2018-02-13 mbed_official Merge pull request #135 from adbridge/master
55:f17578ef784d 2018-01-31 mbed_official Merge pull request #134 from cmonr/master
54:104348482690 2018-01-17 mbed_official Merge pull request #133 from adbridge/master
53:6c17dd0c6700 2018-01-09 mbed_official Merge pull request #129 from adbridge/master
52:5844d6e60607 2018-01-08 mbed_official Merge pull request #132 from pan-/remove-mbedignore
51:13e52fb622ba 2017-12-20 mbed_official Merge pull request #126 from ARMmbed/mbed-os-5.7.0-oob
50:beea1112dba7 2017-12-05 mbed_official Merge pull request #119 from adbridge/master
49:5e53aded0e2f 2017-11-23 mbed_official Merge pull request #115 from adbridge/master
48:5d8484f69181 2017-11-07 mbed_official Merge pull request #113 from adbridge/master
47:1f5335ea3f67 2017-11-03 mbed_official Merge pull request #110 from 0xc0170/master
46:6b66d08f304e 2017-11-01 mbed_official Merge pull request #112 from marcbonnici/master
45:74b28c5d183b 2017-10-11 mbed_official Merge pull request #108 from adbridge/master
44:dfb005855532 2017-09-29 mbed_official Merge pull request #106 from 0xc0170/master
43:7d141add5c76 2017-09-20 mbed_official Merge pull request #103 from ARMmbed/5.6_sanity
42:973ff161ec9f 2017-09-08 mbed_official Merge pull request #102 from adbridge/master
41:43801c2d0a0c 2017-08-08 mbed_official Merge pull request #100 from 0xc0170/master
40:e28d9bf02152 2017-07-28 mbed_official Merge pull request #99 from bcostm/add_disco_l475vg
39:87d034cbd3fd 2017-07-19 mbed_official Merge pull request #97 from 0xc0170/master
38:e8f13e3607b6 2017-07-19 mbed_official Merge pull request #98 from apalmieriGH/master
37:cbd4d01daf52 2017-07-11 mbed_official Merge pull request #93 from adbridge/master
36:ba2e2bb2a6d1 2017-06-22 mbed_official Merge pull request #89 from adbridge/master
35:5751379340de 2017-06-22 mbed_official Merge pull request #90 from apalmieriGH/master
34:2348da734fd2 2017-06-20 mbed_official Merge pull request #88 from adbridge/master
33:569fa15b1a6a 2017-06-15 mbed_official Merge pull request #83 from apalmieriGH/master
32:d45aa4887a45 2017-06-08 mbed_official Merge pull request #82 from adbridge/master
31:409bf0fe91b5 2017-05-25 mbed_official Merge pull request #81 from adbridge/master
30:dacb92ff8643 2017-05-10 mbed_official Merge pull request #79 from adbridge/master
29:7a6aff8c9468 2017-05-10 mbed_official Merge pull request #78 from ashok-rao/master
28:b8afe00e80bb 2017-05-09 mbed_official Merge pull request #77 from 0xc0170/master
27:fcf8cfa1baf7 2017-04-05 mbed_official Merge pull request #70 from 0xc0170/master
26:0b9298e51d5c 2017-04-05 mbed_official Merge pull request #72 from pan-/update_bluenrg_ref
25:39d162b35fda 2017-04-05 mbed_official Merge pull request #71 from pan-/fix_bluenrg_reference
24:9595ff320573 2017-03-14 mbed_official Merge pull request #68 from adbridge/master
23:bcef5a68b77a 2017-03-09 mbed_official Merge pull request #66 from ARMmbed/oob_test_mbed-os-5.4
22:ed95da90a14b 2017-03-01 mbed_official Merge pull request #55 from adbridge/master